What is Cobalt Alloy?
Cobalt alloy is a metal material with cobalt as the main component. Various alloy systems are formed by adding different proportions of chromium, nickel, tungsten, molybdenum, iron, and other elements. These alloys not only inherit the excellent properties of cobalt itself, such as high melting point, good thermal shock resistance, and fatigue resistance, but also further improve their wear resistance, corrosion resistance, and high-temperature stability through the interaction between elements.
What is the Using Environment of Cobalt Alloy?
Cobalt alloys are widely used under various conditions due to their excellent wear resistance, corrosion resistance, and high-temperature stability. The following are some common conditions for the use of cobalt alloys.
High-temperature engine parts: Cobalt-based alloys are often used to manufacture high-efficiency engine parts, such as gas turbine blades, impellers, and ducts, because they can maintain excellent performance at high temperatures. The heat resistance of cobalt-based alloys comes from the refractory carbides formed inside them. These carbides are difficult to convert into solid solutions and have low diffusion activity so that they can maintain high strength and hardness at high temperatures.
Aerospace field: Cobalt-based alloys are also an important material in aerospace technology. Especially in the structural materials of aviation turbines, cobalt-based alloys containing 20%-27% chromium can achieve high oxidation resistance without additional protective coatings, thereby adapting to extremely high-temperature environments.
Wear-resistant parts: Cobalt alloys perform well in wear environments, such as valve parts, pump plungers, steam turbines, high-temperature bearings, etc. These parts should withstand more excellent wear and corrosion during operation, and cobalt alloys’ wear and corrosion resistance can effectively extend their service life.
Food processing equipment: In the food processing industry, cobalt alloys are also often used to manufacture equipment that requires high wear and corrosion resistance, such as needle valves, hot extrusion dies, etc. When these devices come into contact with food, the non-toxicity and stability of the materials must be ensured, and cobalt alloys meet these requirements.
Common Name for Cobalt Alloy?
- The Unified Numbering System for Metals and Alloys is a system of numbers commonly known as the UNS. It is widely accepted in North America. The number consists of an English letter and five numbers. UNS R30006, UNS R30012, UNS R30016, etc. are cobalt alloys.
- ASTM F1537 covers the material requirements of wrought cobalt-28-chromium-6-molybdenum alloy used for surgical implants. This specification specifies that it applies specifically to wrought bar products.
- ASTM F75 covers the requirements for unfinished cobalt-28chromium-6molybdenum (UNS R30075) investment product alloy castings for surgical implant applications and casting alloys of the same in the form of shot, bar, or ingots to be used in the manufacture of surgical implants. This specification does not apply to completed surgical implants made from castings. Both product castings and casting alloys shall conform to specified chemical composition and mechanical requirements, including ultimate tensile strength, yield strength, elongation, and area reduction. Product castings shall additionally undergo liquid penetrant, radiographic, metallographic, and hardness examination.
- Stellite® is the trademark of Kennametal; it is a cobalt alloy.
- BISHILITE® is also a trademark for specific cobalt alloy compositions used in various industrial applications.
- Wallex™ 12, Wallex™ 40, Wallex™ 45, Wallex™ 50, Wallex™ 55, etc. are cobalt-based alloys too.
These alloys are known for their high wear resistance, corrosion resistance, and ability to retain their properties at elevated temperatures, making them suitable for demanding environments.
